This invention relates generally to flying shears, and more particularly to an improved spring return mechanism for flying shears.
Flying shears are well-known in the art of metal fabrication and handling. A detailed description of such device is shown in FIG. 1 and more fully described herebelow. These flying shears are generally adapted to shear long or continuous lengths of stock material into shorter segments at high volume. The stock material is in continuous longitudinal motion through mating apertures in the movable and stationary blades of the flying shear. When the movable blade is activated to effect shearing, the entire flying shear mechanism is transported by the moving stock a short distance during the shearing operation and then returned longitudinally to its original position.
Because of the great demand placed on flying shears, the timing for returning the movable blade back up to its at rest position wherein the stock material may continue to feed longitudinally through the aligned apertures in both movable and stationary blades is quite short. A battery of conventional coil or compression springs acting in tandem or parallel are normally utilized beneath the lower horizontal margin of the movable blade to quickly return the movable blade to its at rest position.
Technology now dictates that the movable blade act in its downward motion at a diagonal angle to the length of the stock material so as to effect a higher quality and more effective shearing action of the stock material. Thus, the conventional spring return system beneath the movable blade in the form of the battery of compression springs is typically disposed at the same diagonal angle (typically 60.degree. to horizontal) as is the movement of the movable blade.
This conventional battery of compression springs quickly wears because of the extremely abusive environment in which they act. Of course, once the battery of springs has lost strength and effectiveness, the entire flying shear must be disassembled by removing the movable blade for replacement of these coil compression springs.
The present invention provides an easily serviceable and considerably more reliable and durable spring return mechanism for use in conjunction with these flying shears. In fact, applicant has found in experimentation that the present invention will last as many as 100 times longer than the conventional battery of return springs used in flying shears.